How hot can it get before rail is damaged?

 
  ANR Deputy Commissioner

With temps in Port Augusta and beyond getting to 47 degrees C, how hot does it need to get before rail infrastructure is impacted?

Do the lines start buckling with 47 degree C, temps and 1.8 km long double stacked trains?

Does the ARTC halt operations to cooler hours?

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  NG Sulzers Deputy Commissioner

Location: Quorn
I'm a Port Augusta based driver that works Adelaide to Berrimah. Trains have been running generally to schedule or better over the recent hot spells.

No special restrictions have been put in place recently due to extreme heat, although a Train Controllers 'get out of jail free card' is to advise drivers to 'drive to the conditions'.
  michaelgm Chief Commissioner

I'm a Port Augusta based driver that works Adelaide to Berrimah. Trains have been running generally to schedule or better over the recent hot spells.

No special restrictions have been put in place recently due to extreme heat, although a Train Controllers 'get out of jail free card' is to advise drivers to 'drive to the conditions'.
NG Sulzers
Drive to the conditions, love it. My ar$e is covered.
Tarcoola was one of  if not the hottest place in the country yesterday @ 49 degrees.
Suggesting a name change to Tarhotter.
  mawsonboii Junior Train Controller

Location: Banned
On hot days, steel rails exposed to direct sunshine can become 20C hotter than the air temperature, The resulting expansion can cause extreme compression and buckling. When this happens, lines become impassable and close for repairs, which can't usually happen until temperatures drop again.
Although I don't think we've ever seen this happen (on metro lines) it does happen and speed restrictions are normally put in place and services can be reduced to not put extra pressure on the train lines.

As for freight lines, I'd assume similar protocol is used. I know the tracks are checked regularly regardless of the weather but I'd assume in extreme heats the rails would be monitored more closely.
  james.au Chief Commissioner

Location: Sydney, NSW
How does a driver drive to conditions with hot rails?  Id expect that a driver would know how to react with wet rails, but hot rails would be a somewhat difficult thing to assess and manage trains on no?  ie, how as a driver do you know how to manage your train on 'hot' rails.

Also other question, if rails are hot, how hot are wheels?  Is wheel temperature measured?
  steam4ian Chief Commissioner

Continuously welded rails are installed to be under tension up until a certain temperature.

Is there a track expert here who knows what that temperature is for various sections of the network?

The last significant heat buckle I recall was on the Seaford line at Clarence Park on the up side about 4 years ago.
A contributing factor could have been the shade afforded by the trees on the roadside which would have caused differential heating of the two rails.
  ARG706 Chief Commissioner

Location: SA
I think I've mentioned this before, but I was on a 3000 on class set (probably 14-17 years ago) passing through the parklands immediately south of the Torrens River bridge heading towards Adelaide, and the rails were like a sleeping snake. As in literally a zigzag, in such a state that traversing the section at at 15kph would cause a derailment. The driver contacted train control and then continued on at about 2-3kph and made it through without any damage to the actual railcars.

I have no idea what happened with the following services after this was identified, but I suspect that it would be treated more seriously today than what it was back then.
  pafcmachine Junior Train Controller

Location: Adelaide SA
I'm not an expert, but rail stress free temperature in SA is about 38 degrees. It varies a bit around the place, but its generally in that vicinity throughout Australia.

When rail is installed or repairs made, the rail temperature is measured and stress in installed in the track by pulling it, or allowing it to cool to allow for expected operating temperature range.

Lots of other variables in track buckles other than rail stress. For example, Rail joint type Continuously Welded Rail vs plated track, sleeper type/condition, Fastening type/condition, ballast condition/shoulder compaction.

I trust this is of interest.
  justapassenger Chief Commissioner

The last significant heat buckle I recall was on the Seaford line at Clarence Park on the up side about 4 years ago.=
steam4ian
You might be thinking of this photo?



Just goes to show that time flies as that was on 28 January 2009, the day when Adelaide recorded its all-time highest maximum temperature of 45.7°C and then the highest daily minimum temperature of 33.9°C. That was early on in the same heatwave which later saw the Black Saturday bushfires in Victoria.

The inner half of the Noarlunga line was then rebuilt in 2013 with continuously welded rail, which works quite well in Adelaide thanks to the relatively mild winter minimum temperatures.

The various issues with the Rail Revitalisation projects have been discussed at length on this forum and don't deserve to be rehashed at length, but it can't be denied that they got this bit right. I recall there being a few times where crews have been called out to hose down the rails to keep trains running, but don't remember any closures due to heat buckle on post-rebuild tracks.
  ARG706 Chief Commissioner

Location: SA
Just for your info, the highest temperature on record for Adelaide was 46.1°C on 12/01/1939. Although 2008 and 2009 were shocking temperature wise, and it makes me wonder how many services were canceled due to buckled track alone.

Is it common for the engines in the railcars to overheat?
  neillfarmer Chief Train Controller

I'm not an expert, but rail stress free temperature in SA is about 36 degrees. It varies a bit around the place, but its generally in that vicinity throughout Australia.

When rail is installed or repairs made, the rail temperature is measured and stress in installed in the track by pulling it, or allowing it to cool to allow for expected operating temperature range.

Lots of other variables in track buckles other than rail stress. For example, Rail joint type Continuously Welded Rail vs plated track, sleeper type/condition, Fastening type/condition, ballast condition/shoulder compaction.

I trust this is of interest.
pafcmachine
The track gangers I chatted with a few months back said the happy track temperature in Queensland Metro area is 38 C.
(to see what happy track is you will have to buy the February 2019 issue of Trains and read page 62).
Neill Farmer
  michaelgm Chief Commissioner

Channel 10 news, Sydney sHowled footage last night of fire brigade hosing the line around Mittigong due to heat. Appeared to be down main as what I think was the up empty garbage train with two 81,s on point passed by headed to Sydney. Curiously it was moving at a fair clip.
  theanimal Chief Commissioner

Channel 10 news, Sydney sHowled footage last night of fire brigade hosing the line around Mittigong due to heat. Appeared to be down main as what I think was the up empty garbage train with two 81,s on point passed by headed to Sydney. Curiously it was moving at a fair clip.
michaelgm
In Melbourne on a flyover there is a sprinkler system that sprays water onto the web of the rail.
  mawsonboii Junior Train Controller

Location: Banned
When I say driving to the track conditions, I mean train services travel at a lower speed and the tracks are monitored. It's the rails in long periods of direct sun light that are at risk and again it has to be extremely hot for a number of days in a row before any issues may to arise, though unlikely, but as mentioned above during our last big heatwave that saw several days well above 40C rails did fail.
  ANR Deputy Commissioner

Port Augusta today is forecasted to reach a temp of 49 degrees C,. According to BoM observations, it hit 47 degrees at 1.30pm.

Would drivers feel it safe to be riding the rails today in SAs mid north? How good is the cabin air-con in an NR loco, let alone the engine cooling system?

With temps like these, Marble Bar and Oodnadatta might lose their claim to fame.
  justapassenger Chief Commissioner

No problem with the rails today, it was various items of electrical equipment which suffered first.
  mawsonboii Junior Train Controller

Location: Banned
you guys may find this video interesting. it's the other weather extreme, FROZEN.

https://www.youtube.com/watch?v=REhIqRa3zO4

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